Methods for distinguishing between human males and females have been proposed in various fields. For example, Unexamined Japanese Patent Application JP-A-2001-218020 teaches an image processing method that identifies the gender of a person seen in a camera photo based on the person's appearance and carries out image data processing for enhancing the looks of the photographed subject based on the result of the gender identification. Unexamined Japanese Patent Application 10-293837 teaches a system for acquiring marketing information by installing a gender identification system at the entrances of various kinds of halls, stores and the like and counting the number males and females among the visitors.
Conventional gender identification methods distinguish the gender of a person by photographing the person with a television camera or digital camera, extracting from those portions of the acquired data related to the person certain portions of interest, such as the face, hands, shoes and personal effects, and analyzing the nature thereof. The specific judgment criteria include, for instance, the center of gravity of the hair mass, how long the arms are kept folded, size of handbag, how long a hand is kept in a pocket, facial makeup, and whether or not the subject is wearing lipstick.
The conventional gender identification methods are thus based on characteristics of the human subject that a person can change intentionally, such appearance and mannerisms, and are therefore apt to be unreliable. Although methods for identifying gender based on voice information are also known, the discrimination is unreliable in this case, too, owing to use of, for example, a technique employing tone of voice; and, moreover, these methods have a drawback in that the scope of use is severely limited by the fact that in order to be able to use voice information the subject must be made to say something.
An object of the present invention is to provide a gender identification method that overcomes the aforesaid shortcomings of the prior art.
Another object of the present invention is to provide a gender identification method that utilizes a bio-characteristic inherent to the human body.